射频干扰对InSAR干涉处理的影响分析

窄带干扰是低频段InSAR系统面临的主要射频干扰之一，它的存在会对干涉相位产生严重影响，进而导致高程反演误差。本文推导了窄带干扰影响下的InSAR干涉相位的解析表达式，给出了干涉相位对窄带干扰各参数的敏感度方程，仿真分析了窄带干扰对P波段InSAR系统干涉处理的影响。结果表明，窄带干扰经过成像后其幅度调制函数近似为方位时间的sinc函数，在SAR图像中表现为沿距离向的干扰条带。干涉相位对窄带干扰信号的功率较敏感，对其频率较不敏感，干涉相位和高程反演误差随着干信比的增加而增加。

Analysis of the Effect of Radio Frequency Interference Signal on Interferometric Processing of InSAR

Narrow band interference(NBI) is one of the main radio frequency interferences.The presence of NBI has serious influence on interferometric phase.And it can lead to digital elevation model(DEM) reconstruction error.The interferometric phase interfered by NBI is deduced,and the sensitivity of interferometric phase to the parameters of NBI is also given in this paper.By simulation,effects of NBI on P band InSAR interferometric phase and DEM reconstruction are analyzed.The conclusions are that the amplitude of NBI after imaged is approximately sinc function of azimuth time,and NBI brings bright strap in the range direction in SAR image.In addition,interferometric phase is not sensitive to the frequency of NBI but sensitive to the power of NBI.And with the increase of the interference to signal ratio(ISR),both interferometric phase error and DEM error increase.